"I was still one shot ahead going into the 10th and then things went all pear-shaped after that," he said.
"I'll get over it. I'll have plenty more chances - I know that."
McIlroy then logged in to his
to add: "Well that wasn't the plan! Found it tough going today, but you have to lose before you can win. This day will make me stronger in the end.
"Oh and congratulations Charl Schwartzel!! Great player and even better guy! Very happy for him and his family!"
Rory McIlroy's Masters nightmare
McIlroy's disastrous round began with a bogey at the first and he followed that by almost leaving his ball in a fairway bunker on the par-five second when his shot thudded into the front lip.
Fortunately the ball bounced out but he found a greenside bunker with his next shot, only to get up and down for par.
Any thoughts that his good fortune would kick-start his round evaporated on the fifth when he dropped another shot to fall back to 10 under par.
McIlroy settled his nerves with a solid par on six and then drained a 20 foot putt on the seventh to return to 11 under par and a lead of one.
However, his Masters bid started to unravel on the 10th when his tee shot ricocheted way left off a tree and nestled between the cabins that separate the main course from the par-three course.
He hit a low hook back onto the fairway but then missed the green with his third shot, hit another tree with his fourth and finally chipped on with his fifth. Two putts later he was back at eight under par after a triple bogey seven.
McIlroy's nerves were further shredded by a three-putt on 11 and, after finding the heart of the green on the par-three 12th, he contrived to take four putts from inside 20 feet to plummet to five under par.
"I don't think I can put it down to anything else than part of the learning curve," he said. "Hopefully if I can get myself back into this position pretty soon I will handle it a little bit better.
Brit golfers reflect on their Masters
"It will be pretty tough for me for the next few days, but I will get over it - I will be fine.
"There are a lot worse things that can happen in your life. Shooting a bad score in the last round of a golf tournament is nothing in comparison to what other people go through.
"Getting applauded up onto the greens, I was almost a little embarrassed at some points. But the support I had here was fantastic and I really appreciate it.
"I can't really put my finger on what went wrong. I lost a lot of confidence with my putting, but I just hit a poor tee shot on 10 and sort of unravelled from there.
"I'll have plenty more chances I know and hopefully it will build a bit of character in me as well."
McIlroy was not alone in struggling with his putter on Augusta's famed tricky greens with England's
admitting frailties with the flat stick cost him dear.
The world number two, who finished runner-up to
Phil Mickelson last year,
picked up three shots on the front nine to move to six under par but any thoughts of a charge were ended when he double bogeyed the par-three 12th after hitting his tee shot into the water.
"I'm very very frustrated," he said. "I played tee to green like a man who should have won the tournament but I was abysmal on the greens.
"I went to the belly putter which I haven't used for six years but what's bugging me is that I can't hit the hole from four feet.
"I gave myself so many chances so to finish on five under is a killer."
ended the tournament as the highest-placed British golfer, jumping back above Mickelson to third in the world rankings after shooting a three-under-par final round 69 to end tied fourth on 10 under.
“From start to finish I played nicely but I didn't take advantage of holes I should have done”
However, the Englishman was left to rue a double bogey on 12, after also finding the greenside water, and a further dropped shot on the 17th as he finished four shots adrift of Schwartzel.
"It was, I imagine, one of the best Masters to watch," said Donald.
"Twelve was a killer for me, it was the one bad swing I made all day and I paid the penalty but I dug in deep and made some birdies [on 15, 16 and 18] but I came up short."
The 75th staging of the Masters proved to be another frustrating major for
who opened with a double bogey on his way to a one-under-par total for the tournament.
"I'm disappointed," he said after signing for a one-over-par 73.
"From start to finish I played nicely but I didn't take advantage of holes I should have done, namely [the par-fives] 13 and 15.
"I'm over par on those holes and it's taken me out of contention.
"I hit four perfect tee shots on 13 and never had more than a four iron into the green and on 15 I made two bogeys and that's just not good enough."
In contrast, Scotland's
thoroughly enjoyed his final day at the 2011 Masters alongside Tiger Woods despite posting a one-over par 73 to drop back to three under.
"It doesn't get much better than that," he said. "I said to my caddie 'enjoy this walk as it's going to be a year until we're back'.
"Overall, what a great week. It is tough to say in words - the atmosphere was incredible [on Sunday].
"Tiger played well and it was fun to be out there. There's a lot of learning on this course and I can't wait to get back here next year."
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